HordeQBF: A Modular and Massively Parallel QBF Solver

TL;DR

HordeQBF is a new massively parallel QBF solver that integrates DepQBF into HordeSAT, demonstrating significant speedups on challenging instances through experimental evaluation.

Contribution

This paper introduces HordeQBF, a modular and massively parallel QBF solver built by integrating DepQBF into HordeSAT, enabling scalable performance improvements.

Findings

Achieves superlinear average speedup on hard QBF instances

Demonstrates effective parallelization of QBF solving

Outperforms previous solvers on benchmark instances

Abstract

The recently developed massively parallel satisfiability (SAT) solver HordeSAT was designed in a modular way to allow the integration of any sequential CDCL-based SAT solver in its core. We integrated the QCDCL-based quantified Boolean formula (QBF) solver DepQBF in HordeSAT to obtain a massively parallel QBF solver---HordeQBF. In this paper we describe the details of this integration and report on results of the experimental evaluation of HordeQBF's performance. HordeQBF achieves superlinear average and median speedup on the hard application instances of the 2014 QBF Gallery.